Merge sort using Java without class level variables

Mergesort :- Only reason to choose this sort is its time complexity is o(nlogn) based on asymptotic analysis.

public class TestClass {

    public static void main(String[] args) {
        // Initialize the array
        int a[] = { 1, 4, 9, 6 };
        mergesort(a, 0, a.length - 1);
        //Finally print the array
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
    }

    private static void mergesort(int[] a, int low, int high) {
        // check if low is smaller then high, if not then the array is sorted
        if (low < high) {
            int middle = low + (high - low) / 2;
            //Recursive call to left and right
            mergesort(a, low, middle);
            mergesort(a, middle + 1, high);
            // Combine them both
            merge(a, low, middle, high);
        }
    }

    private static void merge(int[] a, int low, int middle, int high) {
       //Create temporary error
        int[] temp = new int[a.length];
        for (int i = low; i <= high; i++) {
            temp[i] = a[i];
        }

        //Initialize variables for looping condition
        int i = low;
        int j = middle + 1;
        int k = low;

        //Loop through first and second array and place smallest in main array
        while (i <= middle && j <= high) {
            if (temp[i] < temp[j]) {
                a[k] = temp[i];
                i = i + 1;
            } else {
                a[k] = temp[j];
                j = j + 1;
            }
            k = k + 1;
        }

       //Loop through left over elements
         // Loop through left over elements
        while (i <= middle) {
            a[k] = temp[i];
            i = i + 1;
            k = k + 1;
        }
        while (j <= high) {
            a[k] = temp[j];
            j = j + 1;
            k = k + 1;
        }    }

}